Electric-arc furnace.



L L1; LA coun. ELEcmc ARC funn/acs.. APPLICATION msn N.ov. 221915.

y 1,296,194. Patenfed'Mam, 1919.

To all whom it may concern:

through the same.

UNITED STM-*ns 'PATENT oFFIoE.

JENs LassEN LA coUR, or 'cHRIsTmNIm NORWAY, AssIGNoR :ro- N oasx HYDRO- ELEKTRIsx KVAELSTOFAKTIESELSKAB, oF cHRIsTIAmA, NORWAY.

ELECTRIC-ARC FURNACE.

Be it known that I, .TENS LAssEN LA (IOUR, a subject of the King of Sweden, residing at Christiania, Norway, have invented certain new and useful Improvements in Electric- Arc Furnaces; and I do hereby declare the following to be a full, clear, and exact de' -scription of the invention, lsuch as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings,

.and to letters or figures o f-reference marked thereon, which form a part of this specification.

The present invention relates to improvements in electric arc furnaces, and more particularly -in'furnaces for oxidizing air in a long stable electric arc under high pressure.

In furnaces of this kind, such as Schoenherr-furnaces, working at high pressure- 'twenty atmospheres or more-the variations in-pressure and velocity of gastlow have an injurious inuence on the working of the furnace and in order to remove this disadvantage one has resorted to air' buffers con nected with the gas pipes. y

Buffers 'of 'this kind generally must be 'made of a considerable size and owing t'o this and to thehigh pressure they generally represent a very inconvenient complication of the plant, while at the same time they cause lossof heat. Owing to the high temperatures the material and particularly all connections may easily be damaged.

The object of the present invention is to provide a buffer arrangement for equalizing the shocks' or sudden changes of pressure which does -not present the inconveniences v above referred to, and this object is attained by mounting the buffer directly on the furnace and combining it with thenecessary cooling devices for the furnace gases.; Simultaneously the pressure in the buffer is wholly or. substantially balanced by means ofv an exterior pressure- .of gas, steam o'r liquid, which may be established'either by 'means of an independent arrangementor by means of the combined bui'er and cooling device, vizi, by means of the gases flowing In the latter case the butter may form part of a steam boiler, while in. the former case the space outside the b-uifer 'maycommunicate with a steam boiler' in order to utilize the heat from the buffer.

speciaal-mon gf Lettersrate'nt. Patented Mal-4,1919 Application meanovember 22,1915. serialnasarsa On the drawings :4

top f a tube furnace and a 'buffer according to -theinvention mounted directlyon the same.

rangement according to Fig. 1.*

Referring. to Fig. l a steam boiler is mounted 'directly on topof a tube furnacea, the main tube-c in 'the boiler -b forming. a buffer for'the said tube furnace. `The gases pass through this main heating tube c back through ordinary heatin at the 'outlet as indicated y the arrow. The pressure existing in tube c which is twenty atmospheres and over, is counterbalanced by means4 of the liquid or .steam in the boiler ZJ. According to Fig. 2. the upperwater cooled part d of the furnace a forms part of the water space .in the boiler b, so that according to this arrangement .the heat absorbed in the part d is also utilized for producing steam, circulation of the water contained in the part d andthe boiler b .taking place through openings e. In both of these g'ures 7L is the-water inlet for the boiler, i

the steam outlet therefrom, and k the conductor for the upper end of the vflame tube a, said conductor usually being grounded.

In Fig. 1, Z is the cooling water inlet, and m its exitfrom .the water `jacket surroundingthe conical part g.'

It 1s clear that the samesystem may be `adapted .for any kind of electric arc furnaces, and'it may also be modified to comprise only certain parts of the-buffers.

In case thestability of the furnace does not permit a high decrease in temperature in the buffer itself the iame tube,e. g., the coollng action,'must be reduced inthe irst part of the same or two boilers may .be connected to the furnace with -their flame tubes Fig. 2 shows a modification of the ar;`

tubes and escape electric arc furnace having a fiume tube Whose upper end is contracted and cooled;

of a bu'er mounted on said contracted end and receiving the gases from said furnace, and means heated by the gases issuing from said buer for balancing thegpr'essure in the same.

2. The combination with a highfpressure4 electric arc furnace having a ame tube contracted at one end and said end Watercooled; of a buffer mounted on said contracted end in alinement with said tube and into which said contracted end'discharges, and ame tubes of atubular-boiler into which said bu'er discharges, said buHer op'- erating to equalize pressures in said furnace mospheric pressure in said furnace.

4. The combination with a high pressure electric arc furnace maintaining a high gaseous pressure within the arc chamber; of a buer tube vequalizing furnace pressures above atmospheric pressure andin substantial alinement with the furnace chamber, a water chamber surrounding said tube, the pressure within said chamber counteracting the pressure in said tube, and fire tubes passing through said chamber and receiving hot gases from said buEer tube.

5. The combination of a high .pressure electric arc furnace having a conical end re-` stricting the furnace outlet and at which the arc ends; with a bu'er tube substantially in alinement with the furnace 'chamber and of larger diameter than the contracted discharge end of said furnace, a Water chamber surrounding said buffer tube and fire tubes in said chamber receiving gases from said 7. The combination with a high pressure arc furnace having a Water .cooling-chamber at its upper end; of a bu'er into which said furnace discharges, a Water chamber surrounding the buer, lire tubes in said Water chamber through vwhich the gases expanded in the buHer discharge, and means to'permit the Water of said boiler to enter said cooling chamber.

8. The combination with a high pressure arc furnace having a contracted end surrounded by a Water chamber; of a bilder tube of larger diameter than said contracted end and forming a continuation of the outer Wall of said chamber, a boiler chamber surrounding the buer tube, fire tubes in said y.boiler'chamber through which the buffer tube gases discharge,-and means above the bottom of the boiler chamber to permit circulation of Water from saidboiler chamber through said Water chamber.

1in-testimony that claim the foregoing as my invention, l have signed my name 1n vpresence of two subscribing witnesses.

,i .TENS LASSEN LA COUR. Witnesses:

M. E. GUr'roRMsEN, Tais; BERG. 

